醋酸酯木薯淀粉的特性及在速冻水饺中的应用

对木薯原淀粉和醋酸酯木薯淀粉的冻融稳定性、高温稳定性等性质进行比较。在面粉中添加0%、4%、6%、8%、10%的醋酸酯淀粉,对面团特性进行粉质测定;并将面团做成速冻水饺皮,对水饺皮的蒸煮损失、质构、感官等指标进行综合评价。结果表明,由于在木薯原淀粉中引入了乙酰基,醋酸酯淀粉具有较强的冻融稳定性和高温稳定性,对改善速冻水饺皮品质具有适用性。醋酸酯淀粉对速冻水饺皮蒸煮特性、质构特性等方面有明显的改良作用。最佳添加量为4%～6%。     

酯化蜡质玉米淀粉对糯米粉团冷冻特性的影响

目的评价酯化蜡质玉米淀粉和预糊化酯化蜡质玉米淀粉对糯米粉团冷冻特性的影响。方法测定酯化蜡质玉米淀粉与预糊化酯化蜡质玉米淀粉的冻融稳定性;分别往糯米粉中添加1%、2%、3%、4%(m:m)4个比例的酯化蜡质玉米淀粉和预糊化酯化蜡质玉米淀粉制作速冻糯米粉团,检测速冻糯米粉团的失水率、裂口率、煮熟时间、糊汤率、感官评价等指标。结果预糊化酯化蜡质玉米淀粉与酯化蜡质玉米淀粉均具有良好的冻融稳定性,能有效降低速冻糯米粉团的失水率和裂口率,同时改善速冻糯米粉团的蒸煮和食味品质;预糊化酯化蜡质玉米淀粉在改善糯米粉团冷冻特性斱面效果更优,但两者差距不大,当预糊化酯化蜡质玉米淀粉的添加量为1%时,速冻糯米粉团的失水率为11.8%,裂口率为22.5%,煮熟时间为229 s,吸光度为0.823,感官及外观评分分别为79.3分、23.1分。结论添加1%预糊化酯化蜡质玉米淀粉制成的糯米粉团冷冻特性最好。     

糯玉米醇溶蛋白对速冻水饺品质的影响

以糯玉米为原料,采用超声波辅助提取糯玉米醇溶蛋白,研究了醇溶蛋白的加入方式和剂量对速冻水饺的冻融性、品质的影响.结果表明:玉米醇溶蛋白以1.5%剂量溶于80%乙醇后加入面团,能够提高速冻水饺的冻融稳定性和感官品质.     

冻融循环次数对超声改性玉米淀粉凝胶特性和结构的影响

探讨经超声处理的玉米淀粉在冻融循环过程中其凝胶特性和结构的变化,以期为提升速冻淀粉基食品品质提供理论指导。利用流变仪、物性分析仪、低场强核磁共振仪、傅里叶变换红外光谱仪及X射线衍射仪,分析冻融循环次数对超声改性玉米淀粉凝胶动态流变学和质构特性的影响,并对其结构进行表征。结果表明：不同冻融循环次数下,以天然玉米淀粉作对照,超声改性玉米淀粉凝胶的析水率在第4次冻融时显著下降了5.19%(P<0.05),提高了冻融稳定性;超声改性玉米淀粉凝胶的储能模量和损耗模量降低,凝胶强度变弱;硬度在第4次冻融时显著降低了10.83%(P<0.05),直链淀粉含量下降了0.15%;超声改性玉米淀粉凝胶的碘结合力减弱,横向弛豫时间分布曲线整体左移,短程有序结构减弱,相对结晶度降低。综合凝胶特性和结构表征结果,表明超声处理能够抑制冻融循环过程中玉米淀粉凝胶体系中的水分迁移和双螺旋结构的形成,改善其冻融稳定性。     

青稞粉对速冻面条品质的影响

探讨不同青稞与麦芯粉比例对速冻面条品质的影响。以麦芯粉为对照样品,研究青稞粉对速冻面条品质的影响。结果表明:随着青稞粉混合面粉比例增大,混合面粉面团湿面筋含量逐渐下降,面团形成时间和吸水量逐渐增大;速冻面条品质与青稞粉添加量之间有良好的相关性,青稞粉添加量与面团形成时间、面团吸水量、干物质损失率、咀嚼性呈极显著正相关(P0.01);与湿面筋含量呈极显著负相关(P0.01),与冻融稳定性和TPA弹性呈显著负相关(P0.05);青稞与麦芯粉比例在1∶5~1∶7范围内,速冻面条蒸煮品质和冻融稳定性得到了明显的改善,面条煮后硬度下降,弹性上升,感官品质较好。青稞粉与麦芯粉比例为1∶6时,速冻面条品质最佳。     

蜡质玉米淀粉对速冻肉丸品质的影响

为研究蜡质玉米淀粉对速冻肉丸品质的影响,将蜡质玉米淀粉、木薯淀粉、马铃薯淀粉和玉米淀粉分别添加到速冻肉丸中,对比分析蜡质玉米淀粉肉丸与其他淀粉肉丸的质构特性、冻融循环稳定性和感官特性。结果表明,在不同储藏周期中,添加6%蜡质玉米淀粉肉丸的硬度变化与玉米淀粉肉丸相一致,黏性较低,能较好地改善肉丸的感官品质。此外,在4种淀粉中添加蜡质玉米淀粉的肉丸具有最好的冻融循环稳定性。     

一步法制备冻融稳定型复合变性淀粉及其性质研究

以玉米淀粉为原料,三偏磷酸钠、三聚磷酸钠为交联酯化剂,通过一步法制备交联酯化复合变性淀粉。采用Box-Behnken优化设计对制备工艺进行优化,最佳工艺条件为:反应温度130.62℃,反应时间126.71 min,pH 9.78,含水量23.85%,制得复合变性淀粉析水率为11.76%。经4次冻融循环后复合变性淀粉析水率仅为15.86%,具有良好的冻融稳定性。冻融稳定型复合变性淀粉的糊化开始温度降低至35.3℃、透光度增加至79.5%、磷含量为0.18%、抗凝沉性良好。这些特性使其可以改善冷冻食品的品质,在速冻食品中得以广泛应用。     

食品中淀粉-亲水胶体复配的研究进展

食品工业中复配是指两种或两种以上原料通过恰当的比例,经物理方法混匀,以达到改善食品品质,便于食品加工的目的。适当的将淀粉与亲水胶体复配在改善食品的品质的同时,能够降低食品生产成本。本文从淀粉-亲水胶体复配物的流变学、热力学、糊化性质、凝胶特性、冻融稳定性、热力学性质五个方面进行了论述。对淀粉与亲水胶体相互作用的可能的机理进行了归纳。并对复配物在冰淇淋、果冻、速冻食品等食品的加工中的应用进行了总结。      

魔芋淀粉理化性质研究

为了对魔芋淀粉进一步开发利用提供理论依据,本实验对魔芋淀粉的透明度、老化度、可溶率和膨胀度、直链淀粉和支链淀粉含量、冻融稳定性等理化性质进行研究。结果表明,魔芋淀粉中支链淀粉的含量均高于马铃薯和玉米,其透明度、可溶率、老化值及冻融稳定性均优于马铃薯和玉米淀粉,是一种品质优良的食用淀粉。     

变性淀粉对冷冻面团面包品质的影响

以木薯淀粉为原料,主要研究了预糊化淀粉、羟丙基二淀粉磷酸酯和乙酰化二淀粉磷酸酯三种变性淀粉的物化特性与冻融稳定性,以及它们对冷冻面团面包比容及面包全质构的影响。实验结果表明:木薯淀粉经过不同方式的变性后,物化特性差异很大,其中,羟丙基二淀粉磷酸酯的冻融稳定性最好,预糊化淀粉的冻融稳定性最差;添加5%三种变性淀粉后均能显著延缓冷冻面团的下降趋势,并对冷冻面团面包的品质具有良好的改善作用。这一结果与变性淀粉冻融稳定性及冷冻面团面包比容变化趋势一致,进一步表明变性淀粉,尤其是羟丙基二淀粉磷酸酯可以有效抑制冷冻面团内部水分的迁移,降低冻藏过程中冰晶和重结晶的形成,从而改善冷冻面团面包的内部质构。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press